This NASA image obtained January 31, 2012 and taken by NASA's Near Earth Asteroid Rendezvous mission in 2000 shows a close-up view of Eros. (NASA /Via AFP/Getty Images)

President Obama’s proposed asteroid-lassoing mission, a key piece of NASA’s plan for human spaceflight in the next decade, is trying to make it through the House of Representatives without getting blown to smithereens.

Republicans have taken dead aim at the mission, while also pushing for sequester-level NASA spending and sharp cuts in the agency’s Earth science funding, much of which goes to research on climate change.

The House Committee on Science, Space and Technology, voting on party lines, passed a NASA authorization bill Thursday that would specifically prohibit the agency from moving forward with the Asteroid Redirect Mission (sometimes called the Asteroid Retrieval Mission) without first giving Congress more information about the plan.

“While the Obama administration’s asteroid retrieval mission (ARM) may sound out of this world, many questions still remain about whether this costly mission contributes to NASA’s long-term goals,” science committee chairman Lamar Smith (R-Tex.) said in a statement released by his office.

The Democratic-controlled Senate looks more kindly on the mission and on NASA’s top-line budget in general. Sens. John D. Rockefeller IV (D-W.Va.) and Bill Nelson (D-Fla.) on Wednesday introduced legislation that would authorize $18.1 billion for NASA in fiscal 2014. A separate appropriations bill making its way through the Senate would give NASA almost the same amount.

That compares with $17.7 billion in the president’s initial budget request, $16.8 billion in the House science committee bill and $16.6 billion in a House appropriations committee bill. It appears that the Senate and House will have to resolve their significant budget differences in conference, probably after the August recess.

NASA’s asteroid initiative is in preliminary stages, and the capture mission isn’t even an official program yet. The administration caught many people on the Hill and in the space community by surprise when it included the proposal in its 2014 budget request earlier this year.

The plan has robotic and human spaceflight components. First, an unmanned spacecraft would rendezvous with a small asteroid — roughly 20 to 30 feet in diameter — and swallow it with a tent-like contraption. Then the spacecraft would nudge the rock to an orbit around the moon. Astronauts would visit the captured asteroid in the Orion spacecraft that is being developed in tandem with a heavy-lift rocket called the Space Launch System (SLS).

The administration offers multiple justifications for grabbing an asteroid and having astronauts visit it. A key feature of the mission is that it would use hardware and propulsion technology already being built at significant cost. In marketing the plan, the administration and NASA have leaned hard on the notion that this could help with planetary defense in the long term — boosting knowledge about asteroids and creating techniques for someday deflecting a killer rock.

But the plan has myriad uncertainties. NASA has yet to identify an asteroid that is sure to meet the requirements of the mission, such as size, spin, composition and speed relative to the Earth (the critical factor known as orbital dynamics). It’s unclear how much this would cost. One outside study suggested $2.5 billion. NASA officials have said the robotic portion alone — latching onto the rock and hauling it to lunar orbit — would cost a billion dollars.

Smith, the House science committee chairman, says the mission won’t advance NASA’s long-term agenda. “The proposed mission does not advance science, protect us against dangerous asteroids or develop technologies necessary to explore deep space,” he said. “Congress and the American people simply need more information about why an asteroid retrieval mission is necessary before billions of taxpayer dollars are spent.”

NASA has expressed displeasure with the House legislation.

“These proposals would challenge NASA’s ability to ensure America’s preeminence in space exploration, technology, innovation and scientific discovery,” said David Weaver, the chief NASA spokesman. “Neither measure provides funding requested for an important initiative that would identify and track dangerous asteroids, test critical game-changing technologies and utilize the Space Launch System and Orion crew capsule to explore and better understand these important near-Earth objects.”

Nelson, the Florida senator who is a key advocate for NASA and the administration’s strategy, criticized the Republicans in the House for overreaching.

“A committee of politicians doesn’t know better than the experts in aerospace and science,” Nelson said.

He echoed the planetary-
defense rationale for the mission: “Remember what happened to the dinosaurs?”

Rep. Donna F. Edwards (D-Md.) said Republican attacks on the asteroid mission appear to be reflexive anti-Obama politics.

“It almost feels like anything the president proposes, it’s an automatic ‘I’m against it,’ ” she said.

Rep. Steven M. Palazzo (R-Miss.) denied that the vote to stop the asteroid mission had anything to do with Obama, saying the administration simply needs to provide more information before Congress can approve the spending. He said a higher priority is developing the hardware for human spaceflight in the post-
shuttle era.

“My primary goal is launching American astronauts on American rockets from America,” Palazzo said.